Subtract 20/42 from 15/54
15/54 - 20/42 is -25/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 42 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 54 × 7 = 378,
15/54 = 15 × 7/54 × 7 = 105/378 - Likewise, for the 2nd fraction, since 42 × 9 = 378,
20/42 = 20 × 9/42 × 9 = 180/378 - Subtract the two like fractions:
105/378 - 180/378 = 105 - 180/378 = -75/378 - After reducing the fraction, the answer is -25/126
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